Nowadays, a number of financial transactions are carried out in public places through electronic cards, such as debit cards and credit cards. Typically, to complete a financial transaction, a customer is asked to enter a Personal Identification Number (PIN) or a password for authentication. In such cases, entering of the PIN is exposed to prying eyes, resulting in easy hack of the PIN by watching pattern of finger flow while entering the PIN for transaction. Therefore, there are concerns on securing the PIN entries from shoulder surfing while performing the financial transaction using the electronic cards. Further, these concerns are also applicable to any authentication lock pad for entering the PIN for authentication, for example, device locks, lockers, door locks, Point-of-Sale (PoS), automated Teller Machine (ATM), etc where the user is supposed to enter the PIN in public places.